In my next house, I want everything gas.

Well, that is the flavor for today. The problem is that you have to rely on someone else for the gas. (NG or LPG) But, if you can have as much on gas as possible you would need less solar panels. I will use my house as an example. On average I use 4 kw hours a day to heat water. (This is good for electric heating) If I were to use Solar Panels for this electric (very bad idea BTW) I would need an extra 100o watts of panels. I also have an electric range. While it is hard to measure actual output, an educated guess would be 2 kW hours a day on average.

Without heat or AC running, I would use less than 10kW hours a day. This would be a more manageable solar array. (about 3kW for me) I could shave a little more off of that 10 kW hour number but it would be more of a hassle then it is worth right now. What I need to find is a heating and cooling system that runs off of solar thermal energy. Then the backup would be a gas-fired boiler. I will keep looking for this system.